Remote Diagnostic Tool Research Articles

Wave heating of the solar atmosphere.

Magnetic waves are a relevant component in the dynamics of the solar atmosphere. Their significance has increased because of their potential as a remote diagnostic tool and their presumed contribution to plasma heating processes. We discuss our current understanding of coronal heating by magnetic waves, based on recent observational evidence and theoretical advances. The discussion starts with a selection of observational discoveries that have brought magnetic waves to the forefront of the coronal heating discussion. Then, our theoretical understanding of the nature and properties of the observed waves and the physical processes that have been proposed to explain observations are described. Particular attention is given to the sequence of processes that link observed wave characteristics with concealed energy transport, dissipation and heat conversion. We conclude with a commentary on how the combination of theory and observations should help us to understand and quantify magnetic wave heating of the solar atmosphere.

Power-Based Diagnosis of Node Silence in Remote High-End Sensing Systems

Troubleshooting unresponsive sensor nodes is a significant challenge in remote sensor network deployments. While prior work often targets low-end sensor networks, this article introduces a novel diagnostic tool, called the telediagnostic powertracer, geared for remote high-end sensing systems. Leveraging special properties of high-end systems, this in situ troubleshooting tool uses external power measurements to determine the internal health condition of an unresponsive node and the most likely cause of its failure. We develop our own low-cost power meter with low-bandwidth radio, propose both passive and active sampling schemes to measure the power consumption of the host node, and then report the measurements to a base station, hence allowing remote (i.e., tele-) diagnosis. The tool was deployed and tested in a remote solar-powered sensing system for acoustic and visual environmental monitoring. It was shown to successfully distinguish between several categories of failures that cause unresponsive behavior including energy depletion, antenna damage, radio disconnection, system crashes, and anomalous reboots. It was also able to determine the internal health conditions of an unresponsive node, such as the presence or absence of sensing and data storage activities (for each of multiple applications). The article explores the feasibility of building such a remote diagnostic tool from the standpoint of economy, scale, and diagnostic accuracy. The main novelty lies in its use of power consumption as a side channel, which has more availability than other I/O ports, to diagnose sensing system failures.

Infrared thermal imaging of human skin temperature during combined simulated hemorrhage and thermal stress

Digital infrared thermographic imaging (DITI) may be useful as a remote diagnostic tool for assessment of hemorrhagic injury. Under normal ambient temperatures DITI tracks reductions in central blood volume during simulated hemorrhage from changes in forehead skin temperature. This study tested the hypotheses that (1) DITI can detect changes in forehead skin temperature during simulated hemorrhage under elevated ambient conditions, and (2) changes in skin temperature detected with DITI correlate with changes in skin temperature using thermocouples. Ten healthy subjects were instrumented for ECG, beat‐by‐beat arterial pressure (Finometer), forehead skin temperature (thermocouple and DITI) and rested in the supine position for 60 min in a heated chamber (40 °C). Data were collected during continuous lower body negative pressure (LBNP) until pre‐syncope. DITI tracked the progressive reduction in forehead skin temperature during LBNP (baseline 35.9 ± 0.3 °C vs. pre‐syncope 35.3 ± 0.3 °C, p = 0.001). Correlations between DITI and thermocouple measurements throughout the protocol were high (r2 = 0.88), and did not differ at baseline (p = 0.53) or during LBNP (p ≥ 0.20). These data suggest that DITI may be an appropriate surrogate for remote, or non‐contact assessment of skin temperature in elevated ambient conditions and may prove to be a useful tool in the development of future technology for remote triage.

Consultation of Orthopaedics Cases Using Multimedia Messaging Services

Background:Frequently, radiological data is transferred verbally between the Emergency Department (ED) and orthopaedic registrar. Given the different language skills and medical experience of health staff, there is often a limit to the adequacy of the verbal description that could lead to suboptimal patient care. This study proposes that concurrent review of MMS teleradiology with traditional verbal reporting results in a significant therapeutic benefit.Methods:Case notes of 40 patients who presented to ED were reviewed. Images were captured and sent to an Orthopaedic registrar along with a brief clinical synopsis. Information was collected on the diagnosis of the MMS radiograph, need for urgent admission and management plan outlined to ED.Results:Correct diagnosis was made in 27 of 40 cases. Using the latest technology available, MMS teleradiology had 79% sensitivity, 83% specificity and an accuracy of 80%. 50% of paediatric fractures and 60% of undisplaced fractures were diagnosed successfully.Conclusion:MMS teleradiology is not suitable by itself as a remote diagnostic tool. However, when combined with existing clinical practice, it is effective in screening patients, enhances confidence in decision making and communication between doctors.

Observational study of generation conditions of substorm-associated low-frequency AKR emissions

Abstract. It has lately been shown that low-frequency bursts of auroral kilometric radiation (AKR) are nearly exclusively associated with substorm expansion phases. Here we study low-frequency AKR using Polar PWI and Interball POLRAD instruments to constrain its possible generation mechanisms. We find that there are more low-frequency AKR emission events during wintertime and equinoxes than during summertime. The dot-AKR emission radial distance range coincides well with the region where the deepest density cavities are seen statistically during Kp>2. We suggest that the dot-AKR emissions originate in the deepest density cavities during substorm onsets. The mechanism for generating dot-AKR is possibly strong Alfvén waves entering the cavity from the magnetosphere and changing their character to more inertial, which causes the Alfvén wave associated parallel electric field to increase. This field may locally accelerate electrons inside the cavity enough to produce low-frequency AKR emission. We use Interball IESP low-frequency wave data to verify that in about half of the cases the dot-AKR is accompanied by low-frequency wave activity containing a magnetic component, i.e. probably inertial Alfvén waves. Because of the observational geometry, this result is consistent with the idea that inertial Alfvén waves might always be present in the source region when dot-AKR is generated. The paper illustrates once more the importance of radio emissions as a powerful remote diagnostic tool of auroral processes, which is not only relevant for the Earth's magnetosphere but may be relevant in the future in studying extrasolar planets.

A method of determining horizontal structure of the ionosphere from backscatter ionograms

We have developed a technique lor oblique backscatter sounding (OBS) ionogram inversion as a diagnostic tool for the horizontally inhomogeneous structure of the ionosphere. Input data for the method include the leading edge of a backscalter ionogram that is measured through soundings in a given direction, and the vertical electron density profile measured over the sounding station or over some other site lying in the sounding direction. The method may be useful for reconstructing the two-dimensional electron density distribution in a vertical plane aligned with the direction of sounding. The inverse problem has been solved using the Newton Konlorovich method and the Tikhonov regularization method. The algorithm we have developed was tested against model data, that is, OBS ionograms synthesized using geometrical optics calculations for different models of the inhomogeneous ionosphere. Test results demonstrate that our method converges reliably, is stable to measurement errors and provides a good accuracy of reconstruction of inhomogeneous structures with scales of 100 2000 km. This indicates that this method shows promise as an operative remote diagnostic tool for ionospheric irregularities of natural and artificial origin.